The ultimate objective of this program is to develop a hydrodynamic thrust bearing for use in a wide range of continuous flow implantable rotary blood pumps. Development and integration of the MiTi hydrodynamic thrust bearing into rotary blood pumps will enhance overall reliability of this life support system. The proposed development will result in a hydrodynamic thrust bearing design capable of sharing load with pumps such as those that employ pivot bearings reducing friction induced thrombosis. The developed bearing will also be suitable for use with magnetic bearing systems to limit rotor motions in the event of a shock transient or in the event of a catastrophic failure of the active magnetic bearing. During the Phase I effort, l) a parametric thrust bearing design study will be conducted for a nominal 5 liter/min pump; 2) a detailed design of a thrust bearing that minimizes blood shear stresses, ensures good wash flows and can sustain expected steady state and dynamic shock loads will be completed; 3) the designed bearing will be fabricated; 4) two series of tests simulating the expected blood pump environment will be conducted including a final test series at the CCF to assess the potential for any detrimental hemolysis occurring due to passage through the bearing and 5) a final report including the Phase II plan will be established to complete the effort. The key benefit of this effort is the development of a robust bearing to enhance the reliability of rotoray bloodpumps in a simple passive configuration. PROPOSED COMMERCIAL APPLICATIONS: Applications include short duration clinical use and long term implantable bloodpumps in a simple, robust and cost effective package. Estimates are that anywhere from 35,000 to 200,000 patients a year could benefit from an implantable ventricular assist device if one were available.